Alternatives to fossil fuel-based methods of generating power and heating are being implemented globally due to the environmental impact of extracting fossil fuels and the dwindling supplies. Various types of renewable energy generating devices have been proposed. Many of these devices suffer from the disadvantage of only being capable of supplying electricity intermittently. Wind powered turbines are only capable of producing electricity when the wind blows within a certain range of wind speeds. If the wind is too light, there is not sufficient wind to turn the turbine, and if the wind is too strong, use of the turbine in the high wind may damage the turbine.
Devices which utilise tidal power to generate electricity are also well known. These devices can also be intermittent in their supply of electricity. Not only are they dependent on tidal flows, and particularly flows in certain directions, but in the event of failure, they can be expensive to recover and repair. Maintenance delays further exacerbate the problem of intermittent supply.
Commercially, intermittent electricity supplies attract lower wholesale prices than continuous supplies, and accordingly, intermittent supplies such as that provided by wind turbines have to be subsidised to make them economically viable.
Another common problem associated with wind and tidal power systems is, generally, they are not suitable for location near population centres. Accordingly, the electricity they generate has to be transported significant distances, requiring a large infrastructure to be installed, and transmission losses occur.
A further issue with wind and tidal generation is there is no capacity to store the electricity they generate. Not only is the supply of electricity intermittent from these devices, in addition, the time of supply cannot be controlled. Consequently, they could be producing electricity at times of the day when their electricity is not required.